Radiation

For millions of years, the apex predator of the oceans was a bus-sized shark known as the Megalodon. But around 2.6 million years ago they just disappeared. So what could wipe out a 50-ft (15-m) shark? According to a new study, the culprit was a series of supernovae exploding fairly close to Earth.

An international team of researchers has developed novel nanocrystals that allow the radiation dose from a diagnostic X-ray to be much lower, while also enabling higher resolution images at a lower cost.

In more bad news for future voyagers to Mars, a team of scientists has found that the cosmic rays that astronauts will encounter on long space voyages can cause heavy damage to their GI tract. Using animal tissue, they found that the radiation produces both immediate and long term health problems.

Data returned by the ESA-Roscosmos ExoMars Trace Gas Orbiter indicates that astronauts on even short future Mars missions could face significant space radiation hazards and would be exposed to at least 60 percent of their total lifetime career radiation exposure limit.

Europa is regarded as one of the most likely places in the solar system to find life, but where to look for evidence of it? To aid future space missions, a team has drawn up comprehensive maps of the radiation bombarding the moon to determine where explorers must look to find signs of life.

A new computer model could help astronomers to interpret the radiation emitted by supermassive black holes as they rip apart and devour unfortunate stars. These extreme "feeding" episodes are known as Tidal Disruption Events (TDEs), and are thought to be incredibly rare.

A big challenge humanity faces in venturing off Earth and into deep space is how to tackle the dangers of cosmic radiation.​ A team has now discovered a drug treatment that could not only prevent cognitive deficits caused by this radiation, but actually repair damage in the brain after exposure.

A new study has revealed that ozone levels in the heavily populated lower latitudes don't seem to be recovering as well as regions near the poles. Although there isn't yet a clear explanation as to why this is happening, blame may still rest on short-lived ozone-destroying chemicals.

Gamma ray bursts are mysterious signals blasting in from the deepest reaches of space, and we still don’t have much of an idea about what causes them. In order to help unlock the secrets, researchers have managed to recreate mini gamma ray bursts in the lab for the first time.